added comment explaining why I am temporarly altering the tables
added comment explaining why I am temporarly altering the tables


Former-commit-id: 504d8ff2302f3ef61638fa49a9c3e61c9d590ff9 [formerly 95f54dee9bc80c1ccf28ff094e7307923d1e2bfb]
Former-commit-id: 3e255a6d7bb59d657a5d2ebae1ddc5d74708b737
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine